You have it, you worry about losing your dogs, and it seems the use of it will ease your mind so the obvious answer is to keep the Garmin. It is what I recommend and would do in a similar situation.
Despite having some big running dogs, I have not seen a need for a GPS collar so far. Being a technology Neanderthal has been a significant factor in my reluctance but even with dogs that have reached out a quarter mile in open country or even a hundred yards or so in thick cover I have not seen a need for one.
I do use a relatively loud beeper collar with adjustable tone that allows me to hear it from a distance. This helps mitigate some concerns and training with a dash of luck has covered the rest for many years. My ears are suffering the ravages of age so there may come a time I'll have to revise my opinion on a GPS collar. When that time nears, I'll have to make a jump from the Prehistoric Age all the way to the Dark Ages.
